A. Field of the Invention
The field of the present invention relates generally to skateboards and, more specifically, to truck assemblies utilized with skateboards. More particularly, the present invention relates to skateboard truck assemblies that provide a braking capability which allows the rider to reduce the speed of the skateboard so as to improve the safe operation thereof. Even more particularly, the present invention relates to such truck assemblies that automatically brake the skateboard when the rider places the skateboard in a rearward tilt or tail drag position without sacrificing the maneuverability and turning capabilities of the skateboard.
B. Background
Skateboards are one of the more popular forms of human powered sports and recreational devices that are utilized by a rider to move himself or herself across the ground or other surface. The standard skateboard has a generally narrow, elongated platform, commonly referred to as a deck, having a top surface on which the rider stands and a bottom surface against which a pair of wheel assemblies attach to allow the skateboard to roll across the ground in response to gravity and/or propelling action by the rider. The deck is sized to allow the rider to be able to place at least a portion of both of his or her feet on its upper surface when riding the skateboard. As well known by persons familiar with skateboards, the rider typically uses one of his or her feet to push against the ground in order to propel the skateboard and uses the tilting action of his or her body, usually with the feet generally transversely disposed on the deck, to change the skateboard's direction of travel. Although in the past the skateboard deck was usually configured to be substantially planar and primarily made out of wood, modern skateboard decks are known to have a variety of non-planar shapes, including having a generally uplifting front and/or back end, and are made out of a variety of different types of materials, including various metal, thermoplastic and composite materials.
The typical wheel assembly utilized with most modern skateboards comprises a baseplate that is fixedly secured to the bottom surface of the deck, a truck assembly and a pair of wheels rotatably supported by the truck assembly. The typical skateboard truck assembly, which is commonly referred to simply as a “truck”, comprises a hanger that is secured to the baseplate by a kingpin, one or more compressible bushings which permit the hanger to pivot relative to the baseplate and the deck, and an axle which is supported by the hanger. One wheel is rotatably connected to each of the distal ends of the axle. For the standard skateboard, there is a wheel assembly located generally toward each of the front and back ends of the deck and the truck assemblies are fixedly attached to their respective baseplates with mechanical connectors, such as rivets, screws, bolts and/or specially configured adhesives. The pivoting motion allows the rider more control of the skateboard's movement. Typically, the wheels of a modern skateboard are made out of polyurethane or like materials and the various structural components of the truck assembly are made out of metal, such as aluminum or steel, or various composites.
The pair of wheels are typically mounted on a single axle that is substantially parallel to the riding surface. The truck assembly resiliently pivots about its connection with the board and thereby displaces the axle from its usual orientation perpendicular to the median longitudinal axis of the skateboard. The axles are displaced by tilting the board so that the axles each come to lie on a radius of a circle, thereby orienting the wheels so that they steer the skateboard generally along the circumference of the circle. The typical direction of travel for a skateboard is along the longitudinal axis of the deck. When a rider desires to turn the skateboard, he or she leans generally perpendicular to the direction of travel in the desired direction of the turn, thereby causing the hangers to pivot relative to the deck and turn the skateboard in that direction. Even when turning, the wheels on each truck of the skateboard have a similar direction of travel and follow the intended path of the skateboard. The arrangement of the wheels provides favorable cornering characteristics along with stability, enabling a skilled rider to negotiate smooth, sharp turns in rapid succession.
In learning how to ride a skateboard, and even later after a person becomes proficient in the use of a skateboard, it often becomes necessary to abruptly stop the skateboard to avoid danger, such as when an impediment is suddenly thrust into the skateboard rider's path of movement. Typically, the only way for a rider to stop his or her skateboard, at least commonly in use today, is for the rider to drag a foot along the riding surface, drag the tail of the skateboard deck on the riding surface or quickly dismount and let the board continue to move forward, resulting in the skateboard contacting the obstruction in the path of movement. None of these methods is particularly safe or effective. The problem with regard to stopping or slowing a skateboard is particularly evident when the skateboard is being ridden down a relatively steep and/or long hill. In such circumstances, the skateboard can often reach speeds that make the rider uncomfortable and which can be unsafe for the rider, particularly if he or she is a relatively novice rider. For many uses of standard skateboards, a mechanism for slowing down the skateboard without the rider having to get off the skateboard would be useful.
When a person rides a skateboard down a slope, he or she typically controls the speed of the skateboard by performing a generally zigzag movement that slows the speed of the skateboard, thereby allowing the rider to safely control the skateboard. Some skateboards have a brake device that is used to brake the skateboard when needed. In some prior art configurations, a conventional brake device is controlled by use of a brake cable that interconnects a hand-held brake lever and a brake mechanism that is located beside the wheels. A limitation of this type of braking device is that the rider cannot perform certain movements, which are somewhat commonly performed, if he or she has to grasp a brake lever in a his or her hand. One of the problems with any skateboard braking surface is the movement which the skateboard truck axle makes during the normal riding operation of the board. As stated above, the skateboard is intended to pivot from side to side with respect to the ground surface, since this is the manner in which the skateboard is turned. Any braking pad which is held by the skateboard itself, therefore, moves with respect to the wheel as the board is turned. As such, the braking pad of any braking system must be designed with a great deal of leeway and complexity to permit contact between the board and the axles when they are independently movable.
Over the years, various skateboard braking devices have been patented to improve the operation and safety of a skateboard. For instance, U.S. Pat. No. 3,288,251 to Sakwa discloses a skateboard brake system that uses a deck-mounted lever which connects to a pair of brake pads that rub against the outer surface of the wheels. U.S. Pat. No. 4,037,852 to Bayer, et al. discloses a skateboard braking apparatus having a brake with a lever that is located over the rear wheel assembly. When the lever is pressed down by the rider, the braking element contacts the wheels. One embodiment has two brake pads on each side that move outwardly to contact the inner face of the wheel. Another embodiment shows the use of pins that come into friction contact with the interior assembly of the rear wheels. U.S. Pat. No. 4,084,831 to Akonteh, et al. shows a skateboard brake having a braking pedal near the front wheel assembly of the skateboard. When the rider depresses the pedal, a bar rubs against the top of one of the front wheels. There are a number of disadvantages to a skateboard braking system that has a brake element which rubs against the outer surface of the skateboard wheels. First, the brake element can damage the wheel by its contact. Second, any dirt, water or grease on the wheel, which occurs often, can negatively impact the braking force exerted by the braking element when it rubs against the outer surface of the wheel.
Various prior art skateboard braking systems are incorporated into the wheel assembly below the lower surface of the deck. For instance, U.S. Pat. No. 6,793,224 to Stratton discloses a skateboard truck that includes an arm carried by the base and a spring-loaded linkage interconnecting the base and the arm to bias the arm towards a center position that is aligned with the skateboard's direction of movement. U.S. Pat. No. 6,315,304 to Kirkland et al. discloses an adjustable truck assembly for a skateboard that generally comprises an axle housing, a base, a kingpin connecting the axle housing and base, a turning mechanism between the axle housing and base around the kingpin consisting of opposed cam surfaces that are angled along the axis of the kingpin, an elastomeric bushing and an adjustment mechanism for adjusting the pressure against the bushing. These components are configured such that rotating the axle housing about the kingpin pushes the cam surfaces apart against the compression pressure of the elastomeric bushing. U.S. Pat. No. 6,523,837 to Kirkland discloses a similarly configured adjustable truck assembly, having a retainer that provides a large turning radius for the axle, a highly predictable turning performance and tool-less adjustment of the turning performance. U.S. Pat. No. 6,224,076 to Kent and U.S. Pat. No. D439,945 to Kent disclose a pneumatic compression strut skateboard truck assembly that utilizes a pneumatic compression strut suspension system, which is generally similar to that utilized in automobiles and other mechanical devices which employ shock absorbing technology. U.S. Pat. No. 5,971,411 to Jones, et al. discloses a skateboard truck that generally comprises an extruded skateboard truck base having an angled aperture for a cushion on which a hanger rests and a pivot bolt that holds the hanger to the base and allows weight placed on either side of the skateboard to put pressure on the cushion to facilitate a turn. U.S. Pat. No. 5,263,725 to Gesmer, et al. discloses a skateboard truck assembly having yoke, pivot pin and coil springs to provide rapid and consistent axle rebound to the straight-ahead position, consistent and predictable steering response, an improved balance between stability and maneuverability, fine steering control and a wide range of steering radii. U.S. Pat. No. 4,251,087 to Hansen discloses a truck apparatus for skate and skateboard devices that generally comprises an elongated kingpin, a means for affixing the upper end of the kingpin to the bottom of a load carrying platform, a wheel axle carriage assembly pivotally affixed to the lower end of the kingpin and adapted to rotate about the axis of the kingpin, a resilient drag sleeve and turn restoring element compressively disposed between the first and second friction surfaces, and a lock nut for selectively urging the carriage assembly toward the mid-portioned member so as to compress the drag sleeve between the first and second friction surfaces such that the carriage assembly may be resistively and partially resiliently rotated about the axis of the kingpin. U.S. Pat. No. 4,185,847 to Johnson and U.S. Pat. No. 4,176,850 to Johnson disclose skateboard trucks that have a plurality of wheels which are mounted in independent suspension, which generally comprise longitudinally extending arms that carry the wheel axles forwardly or rearwardly relative to a mounting that secures the arms in rotatable fashion to the trucks and which are resiliently biased by means of separate springs or torsion bars. U.S. Pat. No. 4,184,693 to Whitmarsh discloses a skateboard truck which generally comprises a base plate that secures to the underside of a skateboard deck and a spring member, such as a plate spring, that is joined to the base plate by one end and carries a wheel axle near an opposite end. U.S. Pat. No. 4,152,001 to Christianson discloses a truck assembly that comprises an S-shaped leaf spring that attaches to the skateboard and, through a pivot pin, carries a transverse axle-supporting member at the opposite end. A pair of upwardly and inwardly inclined compression springs are engaged by a pin carried by the leaf spring to resist pivotal movement of the leaf spring relative to the axle-supporting member.
While the foregoing patents and other prior art disclose apparatuses and devices that generally provide, or at least are intended to provide, improved braking for a skateboard so as to improve the safe operation thereof, they have certain limitations that have generally prevented full commercial acceptance of their respective inventions. What is needed, therefore, is an improved skateboard truck assembly for use with skateboards that allows the rider to reduce the speed of his or her skateboard without sacrificing control or maneuverability of the skateboard. The preferred skateboard truck assembly should allow a rider to quickly and effectively apply a braking action to slow or stop the movement of a skateboard. Preferably, the truck assembly should allow the rider to automatically brake the skateboard when he or she places the skateboard in a tail drag or rear tilted position. The preferred apparatus should be configured to be easily installed on and utilized with a wide variety of different types of skateboards and be able to enhance the aesthetic appeal of the skateboards.